1. Field of the Invention
The present invention relates to a thyristor comprising a semiconductor body having at least one emitter zone of a first conductivity type adjoining the cathode-side surface, a base zone of an opposite, second conductivity type at the cathode side, and a cathode electrode that shorts the base zone and the emitter zone.
2. Description of the Prior Art
Thyristors of the type generally set forth above are well known in the art. The shorts in such thyristors are generally arranged at the cathode side. The efficiency of the emitter at the cathode side is therefore reduced. The shorts generally occupy a small area, measured relative to the thyristor area, in order to keep the trigger current low and in order to assure the propagation of the trigger event. These small-area shorts are practically unnoticeable given a higher current density when completely flooded by charge carriers.
In view of favorable dynamic properties of the thyristor in some applications, for example in power converters and choppers, it can be desirable to reduce the emitter efficiency at the cathode side or at the cathode side and the anode side into the region of high current density. This means relatively large-area short-circuit regions that would have a disadvantageous effect in the range of low current density, for example for the trigger propagation.